control.c

Linux Kernel 2.6.9 for OMAP1710

	kctl.count = info.owner ? info.owner : 1;
	access |= SNDRV_CTL_ELEM_ACCESS_USER;
	kctl.info = snd_ctl_elem_user_info;
	if (access & SNDRV_CTL_ELEM_ACCESS_READ)
		kctl.get = snd_ctl_elem_user_get;
	if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
		kctl.put = snd_ctl_elem_user_put;
	extra_size = 0;
	switch (info.type) {
	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
		private_size = sizeof(char);
		if (info.count > 128)
			return -EINVAL;
		break;
	case SNDRV_CTL_ELEM_TYPE_INTEGER:
		private_size = sizeof(long);
		if (info.count > 128)
			return -EINVAL;
		break;
	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
		private_size = sizeof(long long);
		if (info.count > 64)
			return -EINVAL;
		break;
	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
		private_size = sizeof(unsigned int);
		if (info.count > 128)
			return -EINVAL;
		if (info.value.enumerated.items > 1024)
			return -EINVAL;
		extra_size = info.value.enumerated.items * 64;
		break;
	case SNDRV_CTL_ELEM_TYPE_BYTES:
		private_size = sizeof(unsigned char);
		if (info.count > 512)
			return -EINVAL;
		break;
	case SNDRV_CTL_ELEM_TYPE_IEC958:
		private_size = sizeof(struct sndrv_aes_iec958);
		if (info.count != 1)
			return -EINVAL;
		break;
	default:
		return -EINVAL;
	}
	private_size *= info.count;
	if (private_size > 1024 * 1024)
		return -EINVAL;
	dimen_size = 0;
	if (!(info.access & SNDRV_CTL_ELEM_ACCESS_DINDIRECT))
		for (idx = 0; idx < 4 && info.dimen.d[idx]; idx++)
			dimen_size += sizeof(unsigned short);
	ue = kcalloc(1, sizeof(struct user_element) + dimen_size + private_size + extra_size, GFP_KERNEL);
	if (ue == NULL)
		return -ENOMEM;
	ue->type = info.type;
	ue->elem_count = info.count;
	if (!(info.access & SNDRV_CTL_ELEM_ACCESS_DINDIRECT)) {
		for (idx = 0; idx < 4 && info.dimen.d[idx]; idx++)
			ue->dimen[idx] = info.dimen.d[idx];
		ue->dimen_count = dimen_size / sizeof(unsigned short);
	}
	ue->elem_data = (char *)ue + sizeof(ue) + dimen_size;
	ue->elem_data_size = private_size;
	if (extra_size) {
		ue->priv_data = (char *)ue + sizeof(ue) + dimen_size + private_size;
		ue->priv_data_size = extra_size;
		if (ue->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
			if (copy_from_user(ue->priv_data, *(char **)info.value.enumerated.name, extra_size))
				return -EFAULT;
			ue->u.enumerated.items = info.value.enumerated.items;
		}
	}
	kctl.private_free = snd_ctl_elem_user_free;
	_kctl = snd_ctl_new(&kctl, access);
	if (_kctl == NULL) {
		kfree(_kctl->private_data);
		return -ENOMEM;
	}
	_kctl->private_data = ue;
	for (idx = 0; idx < _kctl->count; idx++)
		_kctl->vd[idx].owner = file;
	err = snd_ctl_add(card, _kctl);
	if (err < 0) {
		snd_ctl_free_one(_kctl);
		return err;
	}
	return 0;
}

static int snd_ctl_elem_remove(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
{
	snd_ctl_elem_id_t id;

	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
	return snd_ctl_remove_unlocked_id(file, &id);
}

static int snd_ctl_subscribe_events(snd_ctl_file_t *file, int __user *ptr)
{
	int subscribe;
	if (get_user(subscribe, ptr))
		return -EFAULT;
	if (subscribe < 0) {
		subscribe = file->subscribed;
		if (put_user(subscribe, ptr))
			return -EFAULT;
		return 0;
	}
	if (subscribe) {
		file->subscribed = 1;
		return 0;
	} else if (file->subscribed) {
		snd_ctl_empty_read_queue(file);
		file->subscribed = 0;
	}
	return 0;
}

#ifdef CONFIG_PM
/*
 * change the power state
 */
static int snd_ctl_set_power_state(snd_card_t *card, unsigned int power_state)
{
	switch (power_state) {
	case SNDRV_CTL_POWER_D0:
	case SNDRV_CTL_POWER_D1:
	case SNDRV_CTL_POWER_D2:
		if (card->power_state != power_state)
			/* FIXME: pass the correct state value */
			card->pm_resume(card, 0);
		break;
	case SNDRV_CTL_POWER_D3hot:
	case SNDRV_CTL_POWER_D3cold:
		if (card->power_state != power_state)
			/* FIXME: pass the correct state value */
			card->pm_suspend(card, 0);
		break;
	default:
		return -EINVAL;
	}
	return 0;
}
#endif

static inline int _snd_ctl_ioctl(struct inode *inode, struct file *file,
				 unsigned int cmd, unsigned long arg)
{
	snd_ctl_file_t *ctl;
	snd_card_t *card;
	struct list_head *list;
	snd_kctl_ioctl_t *p;
	void __user *argp = (void __user *)arg;
	int __user *ip = argp;
	int err;

	ctl = file->private_data;
	card = ctl->card;
	snd_assert(card != NULL, return -ENXIO);
	switch (cmd) {
	case SNDRV_CTL_IOCTL_PVERSION:
		return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
	case SNDRV_CTL_IOCTL_CARD_INFO:
		return snd_ctl_card_info(card, ctl, cmd, argp);
	case SNDRV_CTL_IOCTL_ELEM_LIST:
		return snd_ctl_elem_list(ctl->card, argp);
	case SNDRV_CTL_IOCTL_ELEM_INFO:
		return snd_ctl_elem_info(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_READ:
		return snd_ctl_elem_read(ctl->card, argp);
	case SNDRV_CTL_IOCTL_ELEM_WRITE:
		return snd_ctl_elem_write(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_LOCK:
		return snd_ctl_elem_lock(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
		return snd_ctl_elem_unlock(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_ADD:
		return snd_ctl_elem_add(ctl, argp, 0);
	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
		return snd_ctl_elem_add(ctl, argp, 1);
	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
		return snd_ctl_elem_remove(ctl, argp);
	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
		return snd_ctl_subscribe_events(ctl, ip);
	case SNDRV_CTL_IOCTL_POWER:
		if (get_user(err, ip))
			return -EFAULT;
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
#ifdef CONFIG_PM
		if (card->pm_suspend && card->pm_resume) {
			snd_power_lock(card);
			err = snd_ctl_set_power_state(card, err);
			snd_power_unlock(card);
		} else
#endif
			err = -ENOPROTOOPT;
		return err;
	case SNDRV_CTL_IOCTL_POWER_STATE:
#ifdef CONFIG_PM
		return put_user(card->power_state, ip) ? -EFAULT : 0;
#else
		return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
#endif
	}
	down_read(&snd_ioctl_rwsem);
	list_for_each(list, &snd_control_ioctls) {
		p = list_entry(list, snd_kctl_ioctl_t, list);
		err = p->fioctl(card, ctl, cmd, arg);
		if (err != -ENOIOCTLCMD) {
			up_read(&snd_ioctl_rwsem);
			return err;
		}
	}
	up_read(&snd_ioctl_rwsem);
	snd_printd("unknown ioctl = 0x%x\n", cmd);
	return -ENOTTY;
}

/* FIXME: need to unlock BKL to allow preemption */
static int snd_ctl_ioctl(struct inode *inode, struct file *file,
			 unsigned int cmd, unsigned long arg)
{
	int err;
	unlock_kernel();
	err = _snd_ctl_ioctl(inode, file, cmd, arg);
	lock_kernel();
	return err;
}

static ssize_t snd_ctl_read(struct file *file, char __user *buffer, size_t count, loff_t * offset)
{
	snd_ctl_file_t *ctl;
	int err = 0;
	ssize_t result = 0;

	ctl = file->private_data;
	snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
	if (!ctl->subscribed)
		return -EBADFD;
	if (count < sizeof(snd_ctl_event_t))
		return -EINVAL;
	spin_lock_irq(&ctl->read_lock);
	while (count >= sizeof(snd_ctl_event_t)) {
		snd_ctl_event_t ev;
		snd_kctl_event_t *kev;
		while (list_empty(&ctl->events)) {
			wait_queue_t wait;
			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
				err = -EAGAIN;
				goto __end_lock;
			}
			init_waitqueue_entry(&wait, current);
			add_wait_queue(&ctl->change_sleep, &wait);
			set_current_state(TASK_INTERRUPTIBLE);
			spin_unlock_irq(&ctl->read_lock);
			schedule();
			remove_wait_queue(&ctl->change_sleep, &wait);
			if (signal_pending(current))
				return result > 0 ? result : -ERESTARTSYS;
			spin_lock_irq(&ctl->read_lock);
		}
		kev = snd_kctl_event(ctl->events.next);
		ev.type = SNDRV_CTL_EVENT_ELEM;
		ev.data.elem.mask = kev->mask;
		ev.data.elem.id = kev->id;
		list_del(&kev->list);
		spin_unlock_irq(&ctl->read_lock);
		kfree(kev);
		if (copy_to_user(buffer, &ev, sizeof(snd_ctl_event_t))) {
			err = -EFAULT;
			goto __end;
		}
		spin_lock_irq(&ctl->read_lock);
		buffer += sizeof(snd_ctl_event_t);
		count -= sizeof(snd_ctl_event_t);
		result += sizeof(snd_ctl_event_t);
	}
      __end_lock:
	spin_unlock_irq(&ctl->read_lock);
      __end:
      	return result > 0 ? result : err;
}

static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
{
	unsigned int mask;
	snd_ctl_file_t *ctl;

	ctl = file->private_data;
	if (!ctl->subscribed)
		return 0;
	poll_wait(file, &ctl->change_sleep, wait);

	mask = 0;
	if (!list_empty(&ctl->events))
		mask |= POLLIN | POLLRDNORM;

	return mask;
}

/*
 * register the device-specific control-ioctls.
 * called from each device manager like pcm.c, hwdep.c, etc.
 */
int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
{
	snd_kctl_ioctl_t *pn;

	pn = kcalloc(1, sizeof(snd_kctl_ioctl_t), GFP_KERNEL);
	if (pn == NULL)
		return -ENOMEM;
	pn->fioctl = fcn;
	down_write(&snd_ioctl_rwsem);
	list_add_tail(&pn->list, &snd_control_ioctls);
	up_write(&snd_ioctl_rwsem);
	return 0;
}

/*
 * de-register the device-specific control-ioctls.
 */
int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
{
	struct list_head *list;
	snd_kctl_ioctl_t *p;

	snd_runtime_check(fcn != NULL, return -EINVAL);
	down_write(&snd_ioctl_rwsem);
	list_for_each(list, &snd_control_ioctls) {
		p = list_entry(list, snd_kctl_ioctl_t, list);
		if (p->fioctl == fcn) {
			list_del(&p->list);
			up_write(&snd_ioctl_rwsem);
			kfree(p);
			return 0;
		}
	}
	up_write(&snd_ioctl_rwsem);
	snd_BUG();
	return -EINVAL;
}

static int snd_ctl_fasync(int fd, struct file * file, int on)
{
	snd_ctl_file_t *ctl;
	int err;
	ctl = file->private_data;
	err = fasync_helper(fd, file, on, &ctl->fasync);
	if (err < 0)
		return err;
	return 0;
}

/*
 *  INIT PART
 */

static struct file_operations snd_ctl_f_ops =
{
	.owner =	THIS_MODULE,
	.read =		snd_ctl_read,
	.open =		snd_ctl_open,
	.release =	snd_ctl_release,
	.poll =		snd_ctl_poll,
	.ioctl =	snd_ctl_ioctl,
	.fasync =	snd_ctl_fasync,
};

static snd_minor_t snd_ctl_reg =
{
	.comment =	"ctl",
	.f_ops =	&snd_ctl_f_ops,
};

/*
 * registration of the control device:
 * called from init.c
 */
int snd_ctl_register(snd_card_t *card)
{
	int err, cardnum;
	char name[16];

	snd_assert(card != NULL, return -ENXIO);
	cardnum = card->number;
	snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
	sprintf(name, "controlC%i", cardnum);
	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL,
					card, 0, &snd_ctl_reg, name)) < 0)
		return err;
	return 0;
}

/*
 * disconnection of the control device:
 * called from init.c
 */
int snd_ctl_disconnect(snd_card_t *card)
{
	struct list_head *flist;
	snd_ctl_file_t *ctl;

	down_read(&card->controls_rwsem);
	list_for_each(flist, &card->ctl_files) {
		ctl = snd_ctl_file(flist);
		wake_up(&ctl->change_sleep);
		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
	}
	up_read(&card->controls_rwsem);
	return 0;
}

/*
 * de-registration of the control device:
 * called from init.c
 */
int snd_ctl_unregister(snd_card_t *card)
{
	int err, cardnum;
	snd_kcontrol_t *control;

	snd_assert(card != NULL, return -ENXIO);
	cardnum = card->number;
	snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
	if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL, card, 0)) < 0)
		return err;
	down_write(&card->controls_rwsem);
	while (!list_empty(&card->controls)) {
		control = snd_kcontrol(card->controls.next);
		snd_ctl_remove(card, control);
	}
	up_write(&card->controls_rwsem);
	return 0;
}